2774results about "Germ cells" patented technology

Methods and materials for culturing primate-derived primordial stem cells are described. In one embodiment, a cell culture medium for growing primate-derived primordial stem cells in a substantially undifferentiated state is provided which includes a low osmotic pressure, low endotoxin basic medium that is effective to support the growth of primate-derived primordial stem cells. The basic medium is combined with a nutrient serum effective to support the growth of primate-derived primordial stem cells and a substrate selected from the group consisting of feeder cells and an extracellular matrix component derived from feeder cells. The medium further includes non-essential amino acids, an anti-oxidant, and a first growth factor selected from the group consisting of nucleosides and a pyruvate salt.

Disclosed herein are cell cultures comprising PDX1-positive endoderm cells and methods of producing the same. Also disclosed herein are cell populations comprising substantially purified PDX1-positive endoderm cells as well as methods for enriching, isolating and purifying PDX1-positive endoderm cells from other cell types. Methods of identifying differentiation factors capable of promoting the differentiation of endoderm cells, such as PDX1-positive foregut endoderm cells and PDX1-negative definitive endoderm cells, are also disclosed.

Stem cells, including mammalian, and particularly primate primordial stem cells (pPSCs) such as human embryonic stem cells (hESCs), hold great promise for restoring cell, tissue, and organ function. However, cultivation of stem cells, particularly undifferentiated hESCs, in serum-free, feeder-free, and conditioned-medium-free conditions remains crucial for large-scale, uniform production of pluripotent cells for cell-based therapies, as well as for controlling conditions for efficiently directing their lineage-specific differentiation. This instant invention is based on the discovery of the formulation of minimal essential components necessary for maintaining the long-term growth of pPSCs, particularly undifferentiated hESCs. Basic fibroblast growth factor (bFGF), insulin, ascorbic acid, and laminin were identified to be both sufficient and necessary for maintaining hESCs in a healthy self-renewing undifferentiated state capable of both prolonged propagation and then directed differentiation. Having discerned these minimal molecular requirements, conditions that would permit the substitution of poorly-characterized and unspecified biological additives and substrates were derived and optimized with entirely defined constituents, providing a “biologics”-free (i.e., animal-, feeder-, serum-, and conditioned-medium-free) system for the efficient long-term cultivation of pPSCs, particularly pluripotent hESCs. Such culture systems allow the derivation and large-scale production of stem cells such as pPSCs, particularly pluripotent hESCs, in optimal yet well-defined biologics-free culture conditions from which they can be efficiently directed towards a lineage-specific differentiated fate in vitro, and thus are important, for instance, in connection with clinical applications based on stem cell therapy and in drug discovery processes.

The present invention provides cell populations that are enriched for mesendoderm and mesoderm, and cell populations that are enriched for endoderm. The cell populations of the invention are useful for generating cells for cell replacement therapy.

Stem cells, including mammalian, and particularly primate primordial stem cells (pPSCs) such as human embryonic stem cells (hESCs), hold great promise for restoring cell, tissue, and organ function. However, cultivation of stem cells, particularly undifferentiated hESCs, in serum-free, feeder-free, and conditioned-medium-free conditions remains crucial for large-scale, uniform production of pluripotent cells for cell-based therapies, as well as for controlling conditions for efficiently directing their lineage-specific differentiation. This instant invention is based on the discovery of the formulation of minimal essential components necessary for maintaining the long-term growth of pPSCs, particularly undifferentiated hESCs. Basic fibroblast growth factor (bFGF), insulin, ascorbic acid, and laminin were identified to be both sufficient and necessary for maintaining hESCs in a healthy self-renewing undifferentiated state capable of both prolonged propagation and then directed differentiation. Having discerned these minimal molecular requirements, conditions that would permit the substitution of poorly-characterized and unspecified biological additives and substrates were derived and optimized with entirely defined constituents, providing a “biologics”-free (i.e., animal-, feeder-, serum-, and conditioned-medium-free) system for the efficient long-term cultivation of pPSCs, particularly pluripotent hESCs. Such culture systems allow the derivation and large-scale production of stem cells such as pPSCs, particularly pluripotent hESCs, in optimal yet well-defined biologics-free culture conditions from which they can be efficiently directed towards a lineage-specific differentiated fate in vitro, and thus are important, for instance, in connection with clinical applications based on stem cell therapy and in drug discovery processes.

The invention relates to methods for culturing human embryonic stem cells by culturing the stem cells in an environment essentially free of mammalian fetal serum and in a stem cell culture medium including amino acids, vitamins, salts, minerals, transferring, insulin, albumin, and a fibroblast growth factor that is supplied from a source other than just a feeder layer the medium. Also disclosed are compositions capable of supporting the culture and proliferation of human embryonic stem cells without the need for feeder cells or for exposure of the medium to feeder cells.

Improved flow cytometer system particularly adapted to use for sex-selected sperm sorting include enhanced sheath fluid and other strategies which minimize stress on the sperm cells, including a 2.9 percent sodium citrate sheath solution for bovine species and a hepes bovine gamete media for equine species. Improved collection systems and techniques for the process are described so that commercial applications of sperms samples as well as the resulting animals may be achieved.

The present invention provides fully human antibodies in a transgenic animal of a desired isotype in response to immunization with any virtually any desired antigen. The human immunoglobulin heavy chain transgene in the foregoing animals comprises a human constant region gene segment comprising exons encoding the desired heavy chain isotype, operably linked to switch segments from a constant region of a different heavy chain isotype, i.e., a non-cognate switch region. Said additional constant region segment comprises a switch region and human constant region coding segment, wherein the constant region coding segment is operably linked to a switch region that it is not normally associated with, i.e., a non-cognate switch region. In the transgenes of the invention, the non-cognate switch region may be a switch region from a different species than the constant region coding segment. The switch region and membrane exons of the invention may comprise a human gamma-2 constant region and the secreted constant region exons are from a human gamma-1 or a human gamma-4 constant region.

The invention relates to methods for culturing human embryonic stem cells by culturing the stem cells in an environment essentially free of mammalian fetal serum and in a stem cell culture medium including amino acids, vitamins, salts, minerals, transferring, insulin, albumin, and a fibroblast growth factor that is supplied from a source other than just a feeder layer the medium. Also disclosed are compositions capable of supporting the culture and proliferation of human embryonic stem cells without the need for feeder cells or for exposure of the medium to feeder cells.

In embodiments of the present invention, a system and method of cytometry may include presenting a single sperm cell to at least one laser source configured to deliver light to the sperm cell in order to induce bond vibrations in the sperm cell DNA, and detecting the signature of the bond vibrations. The bond vibration signature is used to calculate a DNA content carried by the sperm cell which is used to identify the sperm cell as carrying an X-chromosome or Y-chromosome. Another system and method may include flowing cells past at least one QCL source one-by-one using a fluid handling system, delivering QCL light to a single cell to induce resonant mid-IR absorption by one or more analytes of the cell, and detecting, using a mid-infrared detection facility, the transmitted mid-infrared wavelength light, wherein the transmitted mid-infrared wavelength light is used to identify a cell characteristic.

Previous methods for culturing human embryonic stem cells have required either fibroblast feeder cells or a medium which has been exposed to fibroblast feeder cells in order to maintain the stem cells in an undifferentiated state. It has now been found that if high levels of fibroblast growth factor are used in a medium with gamma amino butyric acid, pipecholic acid, lithium and lipids, the stem cells will remain undifferentiated indefinitely through multiple passages, even without feeder cells or conditioned medium. A humanized matrix of human proteins can be used as a basement matrix to culture the cells. New lines of human embryonic stem cells made using these culture conditions, the medium and the matrix, will never have been exposed to animal cells, animal products, feeder cells or conditioned medium.

The present invention provides a non-mouse, including human, pluripotential embryonic stem cell which can:(a) be maintained on feeder layers for at least 20 passages; and(b) give rise to embryoid bodies and multiple differentiated cell phenotypes in monolayer culture.The invention further provides a method of making a pluripotential embryonic stem cell comprising culturing germ cells and germ cell progenitors in a composition comprising a growth enhancing amount of basic fibroblast growth factor, leukemia inhibitory factor, membrane associated steel factor, and soluble steel factor to primordial germ cells under cell growth conditions, thereby making a pluripotential embryonic stem cell.Also provided are compositions useful to produce the pluripotent embryonic stem cells and methods of screening associated with the method of making the embryonic stem cell.

Previous methods for culturing human embryonic stem cells have required either fibroblast feeder cells or a medium which has been exposed to fibroblast feeder cells in order to maintain the stem cells in an undifferentiated state. It has now been found that if high levels of fibroblast growth factor, gamma amino butyric acid, pipecholic acid, lithium and transforming growth factor beta are added to the medium in which the stem cells are cultured, the stem cells will remain undifferentiated indefinitely through multiple passages, even without feeder cells or conditioned medium.

The present invention provides compositions and methods for the production of differentiated mammalian cells. More particularly, the present invention provides cellular differentiation methods employing culturing the cells on a feeder layer or under feeder-free conditions in cell culture and further contacting the cells with an inhibitor of the PI3-kinase pathway for the generation of differentiated mammalian cells from pluripotent mammalian stem cells. Preferably, the differentiated cell is selected from the group consisting of a mesendodermal cell, a mesodermal cell, and an endodermal cell.

This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

A multi-channel apparatus for classifying particles according to one or more particle characteristics. The apparatus comprises a plurality of flow cytometry units, each of which is operable to classify particles in a mixture of particles by interrogating a stream of fluid containing the particles with a beam of electromagnetic radiation. The flow cytometry units share an integrated platform comprising at least one of the following: (1) a common supply of particles; (2) a common housing; (3) a common processor for controlling operation of the units; (4) a common processor for receiving and processing information from the units; and (5) a common fluid delivery system. The integrated platform can include a common source of electromagnetic radiation. A method of the invention comprises using a plurality of flow cytometry units sharing the integrated platform to perform a flow kilometric operation, such as analyzing or sorting particles.

A flow cytometry system (1) for sorting haploid cells, specifically irradiatable sperm cells, with an intermittingly punctuated radiation emitter (56). Embodiments include a beam manipulator (21) and even split radiation beams directed to multiple nozzles (5). Differentiation of sperm characteristics with increased resolution may efficiently allow differentiated sperm cells to be separated higher speeds and even into subpopulations having higher purity.

The present invention provides compositions and methods of using the compositions to alter the developmental potency of a cell. The present invention provides in vivo and ex vivo cell reprogramming and programming methods suitable for autologous cell therapy and regenerative medicine.

Methods and cell culture medium for the generation of human pluripotent embryonic stem cells are disclosed. Human embryonic stem cells are cultured with human granulosa feeder cells, muscle cells, Fallopian ductal epithelial cells, bone marrow stromal cells, and skin fibroblasts and the embryonic stem cells maintain their pluripotent phenotype. The human pluripotent embryonic stem cells can be cultured without feeder cells, and in the presence of supplemental growth factors. The human pluripotent embryonic stem cells can be alternatively cultured with conditioned medium obtained from a cell culture capable of maintaining human embryonic stem cells in a pluripotent state, wherein the cell culture is a human granulosa cell culture.

Disclosed herein are cell cultures comprising definitive endoderm cells and methods of producing the same. Also disclosed herein are cell populations comprising substantially purified definitive endoderm cells as well as methods for enriching, isolating and purifying definitive endoderm cells from other cell types.

Methods and cell culture medium for the generation of human pluripotent embryonic stem cells are disclosed. Human embryonic stem cells are cultured with human granulosa feeder cells, muscle cells, Fallopian ductal epithelial cells, bone marrow stromal cells, and skin fibroblasts and the embryonic stem cells maintain their pluripotent phenotype. The human pluripotent embryonic stem cells can be cultured without feeder cells, and in the presence of supplemental growth factors. The human pluripotent embryonic stem cells can be alternatively cultured with conditioned medium obtained from a cell culture capable of maintaining human embryonic stem cells in a pluripotent state, wherein the cell culture is a human granulosa cell culture.

Methods for obtaining pluripotent (embryonic stem) cells from parthenogenetic embryos, especially primates, are provided. These cells are useful for producing differentiated cells, tissues and organs, especially human and non-human primate cells, tissues and organs.

The invention concerns methods for automated culture of embryonic stem cells (ESCs) such as human ESCs. In some aspects, methods of the invention employ optimized culture media and limited proteolytic treatment of cells to separate cell clusters for expansion. Automated systems for passage and expansion of ESCs are also provided.

The present invention provides methods for stabilizing pluripotent cells through the transcriptional activation of c-myc. Alternatively, the cells are stabilized through the transcriptional activation of c-myc, and the stabilization of c-myc protein levels. c-myc protein can be stabilized through the inhibition of GSK3β or through other components of the cellular machinery that impact on c-myc stability. The invention contemplates the stabilized pluripotent cells produced using the methods described herein. Methods for the identification of compounds that modulate the stabilization of pluripotent cells through modulating transcriptional activation of c-myc, stabilization of c-myc protein levels, and / or inhibition of GSK3β activity are also contemplated.

The present invention discloses and describes pluripotent homozygous stem (HS) cells, and methods and materials for making same. The present invention also provides methods for differentiation of HS cells into progenitor (multipotent) cells or other desired cells, groups of cells or tissues. Further, the applications of the HS cells disclosed herein, include (but are not limited to) the diagnosis and treatment of various diseases (for example, genetic diseases, neurodegenerative diseases, endocrine-related disorders and cancer), traumatic injuries, cosmetic or therapeutic transplantation, gene therapy and cell replacement therapy.

The present invention provides a method of cryopreserving sperm that have been selected for a specific characteristic. In a preferred embodiment, the method is employed to freeze sex-selected sperm. Although the cryopreservation method of the invention can be used to freeze sperm selected by any number of selection methods, selection using flow cytometry is preferred. The present invention also provides a frozen sperm sample that has been selected for a particular characteristic, such as sex-type. In preferred embodiments, the frozen sperm sample includes mammalian sperm, such as, for example, human, bovine, equine, porcine, ovine, elk, or bison sperm. The frozen selected sperm sample can be used in a variety of applications. In particular, the sample can be thawed and used for fertilization. Accordingly, the invention also includes a method of using the frozen selected sperm sample for artificial insemination or in vitro fertilization.